CN101704560A - Technique for desalting sea water, making salt and comprehensively using by-products thereof by utilizing wind energy, solar energy and heat pump technologies - Google Patents

Abstract

The invention relates to a technique for desalting sea water, making salt and comprehensively using by-products thereof by utilizing wind energy, solar energy and heat pump technologies, the main procedures comprise desalting sea water, air-blowing bromine, removing impurities for clarification, heating solar pond and storing halogen, evaporating for concentration, compressing and crystallizing for salt making, brine chemical engineering, etc. the invention desalts sea water, makes salt and comprehensively uses by-products thereof by utilizing wind energy, solar energy and heat pump technologies, organically combines sea water desalting, salt making and comprehensive use of dregs and waste liquor, takes wind energy, solar energy and other renewable energy resources as main energy sources, changes sea salt production from drying on beach in the open air manually to mechanized and automated operation, puts an end to the backward state of sea salt enterprises, can save energy consumption and reduce pollution, can save investment by about 50% and occupied area by 95%, not only lowers production cost, but also recovers 35m<2> of fresh water by producing one ton of salt, thus protecting fresh water resource.

Description

Utilize wind energy, sun power and heat pump techniques to carry out the technology of sea water desaltination, salt manufacturing and byproduct comprehensive utilization thereof

Technical field

The present invention relates to a kind of technology of utilizing wind energy, sun power and heat pump techniques to carry out sea water desaltination, salt manufacturing and byproduct comprehensive utilization thereof.

Background technology

China shoreline is very long, is Salt production big country, but production technology falls behind, and can not realize the factory building modern production, does not conform to modern development in science and technology: (one) produces one ton of sea salt per year will account for coastal beach 250m ², produce 3000 ten thousand tons per year by the whole nation, take 7,500,000 hectares of beaches, take the land resources of a large amount of preciousnesses; (2) open work, with low content of technology, work load is heavy, the production cost height, the performance of enterprises is poor; (3) the sea salt crystallization processes is that shine on open-air beach, restricted by natural condition, can not accomplish high and stable yields, and quality product does not meet food sanitation safe; Old halogen was collected difficulty when (four) sea salt was shone on the beach, and discharging has a strong impact on coastal ecotope arbitrarily; (5) evaporated a large amount of fresh water in the Salt production process, one ton of salt of every product evaporates 35 tons approximately, does not recycle, and causes the resource significant wastage; (6) present vacuum salt production, one ton of salt of every product will consume 280 kilograms of coals, and 30,000,000 tons of salt are produced in the whole nation per year, annually consume coal-fired 8,400,000 tons, the waste resource, atmosphere pollution, the energy-saving and emission-reduction of advocating with country run in the opposite direction.

Summary of the invention

The objective of the invention is to utilize renewable energy source to do sea water desaltination, guarantee the safety of human Freshwater resources, overcome the defective that exists in sea salt, the chemical production technical simultaneously, provide a kind of and can make full use of the technology that wind energy, sun power, heat pump techniques are carried out sea water desaltination, salt manufacturing and byproduct comprehensive utilization thereof.

To achieve these goals, the technical scheme that the present invention takes is to press following processing step:

(1) takes out and receive seawater

Utilize the pipeline extracting seawater, the seawater saltness is 〉=3.5 ° of Be;

(2) seawater physico-chemical pretreatment

At first using the milk of lime of pH value＞12 to transfer the pH value of seawater is 8, adds PH again and be 4.5 polymeric aluminum chlorides solution, and the pH value that makes seawater is 6～6.5 to reach iso-electric point, clarifies then, and the water after the clarification uses for next step; Sediment water is not through there being the dehydration of band vacuum filter, and water repeats reuse, and filter cake is as composite fertilizer material;

(3) adopt reverse osmosis seawater desalination system system tap water and high-concentrated brine

Adopt reverse osmosis seawater desalination system, its flow process is continuous convergent technology, and the group body device is three grades, and every grade all has recuperator and boosting pump, and operating pressure at different levels are at 5.5～11MP ₂In the scope, power consumption is controlled at 2～4kw.h/m ³

Seawater is after desalination, and the bittern saltness rises to 14 ° of Be, 1m by 3.5 ° of Be ³3.5 ° of Be seawater simmer down to 0.245m ³14 ° of Be bittern; Can produce fresh water 750kg after every cubic metre of seawater cleaning, wherein 10% fresh water is made tap water after uf processing, all the other 90% conduct life and agricultural waters;

(4) air blows the bromine system

Bittern concentration is 14 ° of Be after reverse osmosis system desalination, in temperature 〉=30 ℃, under the condition of pressure≤1.5Mpa, utilize ejector to add acid and chlorine, make bittern acidifying and oxidation, make bromide anion become monomers B r liquid, spray into toward dirty from cat head, pressurized air is gone into from the tower pucking,, water vapor and bromine are taken out of outside the tower with the reverse convection current in tower of bromine liquid, through technology system bromines such as absorption, condensation and separation, make bittern obtain evaporation, concentration reaches 16 ° of Be, evaporation fresh water amount 55Kg/m ³, 1m ³3.5 ° of Be seawater simmer down to 0.19m ³16 ° of Be bittern;

(5) analyse except that Ca ²⁺, Mg ²⁺Ion

The bittern that previous step is come suddenly adds and Mg ²⁺Equivalent milk of lime, reaction generates magnesium hydrate precipitate, supernatant liquor is extracted into another container adds and Ca ²⁺The reaction of normal soda ash generates calcium sulfate precipitation, supernatant liquor is entered down in the solar pond of operation and stores up halogen, more than two kinds of throw outs separate processed, water reuses, filter cake is as chemical industry and composite fertilizer material;

(6) solar pond thermal-arrest, heat accumulation, evaporation concentration and and storage halogen

Utilize the gradient difference function of high salinity bittern in the solar pond, absorb solar radiation, carry out thermal-arrest, heat accumulation, bittern is evaporated concentrated, make bittern concentration be raised to 18 ° of Be by 16 ° of Be, temperature by normal temperature be raised to 〉=45 ℃, evaporation fresh water amount 22.7Kg/m ³, 1m ³3.5 ° of Be seawater simmer down to 0.1673m ³18 ° of Be bittern.The volume of solar pond is big simultaneously, utilizes it to store up halogen, can guarantee the production continuity of operation up and down, realizes the material balance of production technique;

(7) heat pump low-temperature evaporation concentration systems

Utilize low temperature high-efficient energy-saving evaporation process, low temperature heat energy is become high temperature heat, temperature 〉=90 ℃ with heat pump compression, add hot brine and evaporate, utilize the heat pump refrigerating function in addition, reduce temperature≤15 ℃ of water in the Water Jet Condenser, improve vaporization efficiency, reduce cooling water amount; From brine temperature 〉=45 that step (6) is come ℃, concentration is 18 ° of Be, and behind heat pump low-temperature evaporation concentration systems, bittern concentration is raised to 25 ° of Be, temperature 〉=60 ℃, and evaporation fresh water amount is 55Kg/m ³, 1m ³3.5 ° of Be seawater simmer down to 0.112m ³25 ° of Be bittern;

(8) Compression Evaporation crystallization salt making system

Bittern concentration is a saturated bittern when being 25 ° of Be, sodium-chlor will be separated out in crystallization when being concentrated to 26 ° of Be, adopt N to imitate secondary steam Compression Evaporation crystallization processes, every effect evaporation area is equal substantially, first heating steam pressure 〉=the 2.2MPa of imitating, temperature to 125 ℃, all the other respectively imitate working pressure, temperature is according to throughput, vapour compressor technical parameter and crystallizer specification and decide, the continuous feeding discharging material of native system is the following current flow process, dump temperature≤65 ℃, bittern concentration is 28 ° of Be, and each imitates compression heating steam, gathers behind the flash evaporation device, the water vapor recompression improves temperature to 140 ℃, again as the thermal source of product drying;

(9) the ion exchange crystallization in motion is sized mixing

The salt slurry that step (8) is discharged carries out solid-liquid separation, and solid salt adds fresh brine sizes mixing, and carries out the ion exchange crystallization in motion, and former crystalline particle is increased, and increases output, the old bittern of 28.5 ° of Be is fully utilized produce the compoiste fertilizer raw material;

(10) waste residue and liquid processing implementation step is as follows:

1. the throw out of sea water preprocessing after filtering, filter cake do to be produced solid-state fertile raw material, by solid-state fertile Technology standard production;

2. calcium-magnesium removing ionic throw out is magnesium hydroxide and lime carbonate, and its treatment process is as follows:

A: lime carbonate is as the stopping composition of solid-state fertilizer or the sclerosis place of banketing.

B: magnesium hydroxide neutralization reaction

Magnesium hydroxide and sulfuric acid carry out neutralization reaction, generate sal epsom liquid, and a part is liquid fertile raw material, and rest part is as the sal epsom product;

3. utilize the essential substance Nacl, the Na that produce in the bittern concentration process ₂SO ₄And Kcl, implement saltcake Repone K method and produce vitriolate of tartar:

(11) other steps such as centrifuge dehydration, drying, sub-sieve, metering and packing etc. are undertaken by traditional chemical technique.

Described reverse osmosis seawater desalting technology is existing proven technique, has popularized in an all-round way and has generally used.

Described Compression Evaporation crystallization salt making technology is existing proven technique, has popularized in an all-round way and widespread usage.

Technology of the present invention has sea water desaltination, bittern evaporation concentrates, Compression Evaporation crystallization salt manufacturing and product drying etc., equipment used such as reverse osmosis high-pressure pump and boosting pump, heat pump and jet of water water pump, vapour compressor etc., all be to use electric motor in the past, driving such as diesel engine or steam turbine, account for more than 30% of total operating cost, now utilizing wind energy to drive wind energy conversion system directly drives, drag three type of drive by one drag two or, wind energy power cost is 0.3 yuan/kw.h, this mode can reduce the power loss when changing between electric energy and the mechanical energy, saves power charge more than 15%, and wind energy is a renewable and clean energy resource simultaneously, pollution-free, make new projects can reach the purpose of energy-saving and emission-reduction.

High concentrated seawater after utilization is desalinated carries out evaporative crystallization salt manufacturing, and producing a ton salt investment estimation is 1500 yuan/ton, and an open-air beach solarization product ton salt investment estimation is 3000 yuan/ton, saves investment 50%, saves floor occupying area 95%.

Produce one ton of sea salt, 3.5 ° of Be seawater 40m ³More than, evaporation fresh water 〉=35m ³After obtain 25 ° of Be saturated bittern 4.5m ³, if adopt traditional open-air solar saltworks technology, the fresh water of evaporation can't reclaim, and one ton of sea salt of the every production of patented technology of the present invention can reclaim fresh water 〉=30m ³, can make with extra care about ecosystem tap water 3 tonnages, by every 500ml, can produce 6000, every net income is 0.1 yuan/, takes in 600 yuan of net incomes altogether, this income can be offset reverse osmosis and heat pump low-temperature evaporation Cost of seawater desalination fully, so obtain 5 ³25 ° of Be saturated bitterns and 35m ³The cost of domestic water and farmland-use water is zero.Utilize such halogen source to do salt manufacturing and chemical industry, its cost reduces more than 20% than other modes certainly.

Sea water desaltination combines with salt manufacturing, Chemical Manufacture, and one, guarantee salt manufacturing and the high-quality low cost movement of Chemical Manufacture; Two, can guarantee the human sea salt of being able to eat multielement; Three, produce one ton of salt and can reclaim 35m ³Fresh water, the human precious Freshwater resources of protection; Four, the comprehensive utilization of waste residue and liquid is produced liquid and solid-state humic acid organic composite fertilizer is the agriculture production service.

Description of drawings

Fig. 1 is a process flow sheet of the present invention;

Embodiment

Technology of the present invention can be implemented, and selects for use equipment very important, and the selected equipment of technology all is general both at home and abroad, according to the processing parameter requirement of throughput, target level of product quality, selects for use by specifications and models.The major equipment drive energy is a wind energy in addition, utilizes sun power for evaporation heat energy, utilizes heat pump techniques to carry out low-temperature evaporation, utilizes Compression Evaporation crystallization salt manufacturing etc.

(1) utilization of wind energy

China's southeastern coast wind energy is very abundant, every m ²Be 200W, wind speed every year of m/s, the wind energy availability drove production unit more than 47% so utilize wind energy to drive wind energy conversion system, is the developing direction of utilizing wind energy on average at 5000-7000 hour.

It is power source that the technology of the present invention adopts three large-scale wind energy wind energy conversion systems, first high-pressure pump that directly drives inductor generator and impervious desalination system; Second heat pump that directly drives inductor generator and low-temperature evaporation concentration systems; The 3rd directly drives inductor generator and multiple-effect Compression Evaporation crystalline vapor-compression machine.Every wind energy conversion system all is that one drag two or drags three type of drive, and when wind-force reached wind rating, wind energy conversion system not only generated electricity and uses for other equipment, drives main equipment simultaneously.When wind speed was not enough, inductor generator utilized dispatch from foreign news agency to become electric motor and drags equipment such as high-pressure pump, heat pump and vapour compressor, and its power configuration is bigger by 15% than driven equipment power.The connecting mode of wind energy conversion system and inductor generator adopts the combination of electromagnetic clutch and overrunning clutch.

Wind energy conversion system transmission principle of work: wind energy driving wind wheel drive horizontal spindle low speed (n=15～45r/min) → break-in is that Z-axis low speed → break-in is transverse axis low speed → speed change gear → electromagnetic clutch and overrunning clutch → inductor generator → flange connection → main equipment (high-pressure pump, heat pump and vapour compressor etc.).

Wind energy conversion system design has automatic speed regulation and inertial flywheel energy storage device, has additionally when treating wind speed decreased, guarantees the blower fan smooth running.

(2) design of solar pond

Solar pond is utilized high salinity bittern gradient difference function, absorbs the radiation of sun power, realizes the effect of thermal-arrest, heat accumulation, evaporation concentration bittern.Its volume capacity should be 3 times that produce every day with the halogen amount, is divided into three groups of ponds and builds, and every day puts into operation in one group of pond, and the specification in every pond is for long: wide=1: 0.5, the longest can not surpassing 〉=100m, the degree of depth is 3m, and is underground-2.4m, on the ground+and 0.6m.Solar pond printing opacity polyester plastics sheet material caping, utilize its evaporation and heat storage capacity that bittern concentration is risen to 18 ° of Be by 16 ° of Be, temperature is 〉=45 ℃, the volume ratio of solar pond is bigger, it has storage halogen function, play and regulate the production continuity of operation up and down, guarantee the process stream balance of production line etc.

(3) electromagnetic heat pump type selecting

The energy transformation of electromagnetic heat pump is more than 〉=98%, and it does not have rotating shaft output, does not have an envelope problem, and water once circulates through pump simultaneously, and temperature of charge can improve 3 ℃, as evaporation in the technology, spissatedly select equipment for use for halogen and circulation.

(4) settling apparatus type selecting

The settling apparatus of sea water preprocessing should be selected continuous inclined plate settler for use, and it is a kind of gravitational settler, and the solid particulate that is scattered in the fluid is relied on the power effect for support, reach the purpose of solid-liquid separation, it is big to have a settling area, and treatment capacity is many, the while facility compact, floor space is little, need not drive unit.In addition the resultant of calcium-magnesium removing be Mg (OH) 2 ↓ and CaCo3 ↓, select for use settling tank to cooperate solar pond to use to good.

(5) this technology is divided into 8 big units: wherein have reverse osmosis seawater desalting can produce the unit of refining ecosystem tap water, domestic water, farmland-use water and 14 ° of Be bittern of high salinity; Air blows the unit of bromine method for system bromine and 16 ° of Be bittern of generation high salinity; Removal of impurities is played thermal-arrest, heat accumulation and storage halogen with solar pond high density bittern gradient difference function and is combined, and makes the unit of bittern evaporation enrichment and intensification; Utilize heat pump principle to realize the unit of low-temperature evaporation bittern enrichment; Utilize the unit of multiple-effect Compression Evaporation crystallization salt manufacturing; Utilize waste residue and liquid to produce the unit of compoiste fertilizer and other Chemicals.More than the major equipment of 8 big unit technical matters, except that special specific equipment, all with both at home and abroad general-purpose equipment is basic identical for remaining, according to process parameters design and select for use.

Concrete processing step is as follows:

(1) fixed point is taken out and is received seawater

Utilize pipe to lead and take out the seawater at deep-sea.Because the seawater saltness height at deep-sea, generally at 〉=3.5 ° of Be, it is few to contain microbial impurities such as algae and bacterium, and the temperature of water is more stable.

(2) seawater physico-chemical pretreatment

Seawater contains silt, and impurity such as colloid and microorganism, these impurity can influence desalting plant and normally move, and reduces the quality of desalination water.At first using the pH value of the milk of lime accent seawater of pH value＞12 is 8, add pH value again and be 4.5 polymeric aluminum chlorides solution, the pH value that makes seawater is 6～6.5 to reach iso-electric point, makes impurity coacervation precipitation in the seawater, and remove part calcium and magnesium ion, clarifying water is that (3) step is used.Sediment water is not through there being the dehydration of band vacuum filter, and water repeats reuse, and filter cake is as composite fertilizer material.

(3) adopt reverse osmosis system system tap water and high-concentrated brine

Method for desalting seawater has several, and wherein reverse osmosis method has advantages such as less investment power consumption is low, so employing desalination by reverse osmosis process system, its flow process is continuous convergent technology, the group body device is three grades, and every grade all has recuperator and boosting pump, and operating pressure at different levels are at 5.5～11MP ₂In the scope, power consumption is controlled at 2～5kw.h/m ³

Seawater through the desalination after, the bittern saltness rises to 14 ° of Be by 3.5 ° of Be, from the 1st step so far the step volume be 1m ³3.5 ° of Be seawater simmer down to 0.245m ³14 ° of Be bittern.Can produce fresh water 750KG after every cubic metre of seawater cleaning, wherein 10% fresh water can be made the ecosystem tap water after uf processing, bottled sale, all the other 90% conduct life and agricultural waters.

(4) air blows the bromine system

Bittern concentration is 14 ° of Be after the desalination of reverse osmosis method system, temperature 〉=30 ℃, pressure≤1.5Mpa utilizes ejector to add acid and chlorine, makes bittern acidifying and oxidation, make bromide anion become monomers B r liquid, spray into toward dirty from cat head, pressurized air is gone into from the tower pucking, with the reverse convection current in tower of bromine liquid, water vapor and bromine are taken out of outside the tower, through technology system bromines such as absorption, condensation and separation.Water vapor contact in saturated air and the tower, is the saturated air humidification process, leave tower body after, be the dehumidification process, make bittern obtain evaporation, concentration reaches 16 ° of Be, evaporates fresh water amount 55Kg/m ³, from the 1st step so far the step volume be 1m ³3.5 ° of Be seawater simmer down to 0.19m ³16 ° of Be bittern.

(5) analyse except that Ca ²⁺, Mg ²⁺Ion

CaCO in the bittern ₃Along with all separating out behind ° Be of concentration 〉=16.75, and calcium sulfate reaches 20.60 ° of Be at bittern concentration, just separates out 64.16%, so during ° Be of bittern concentration≤16, a large amount of Ca are arranged ²⁺, Mg ²⁺Ion will be removed, otherwise the operation evaporation equipment crystallization of influence back, and its method is for to add milk of lime and soda ash in bittern, with magnesium calcium ion equivalent reaction, and the salt of generation indissoluble and precipitating.Reaction formula is as follows:

Mg ²⁺+Ca(OH) ₂→Mg(OH) ₂↓+Ca ²⁺

Ca ²⁺+Na ₂CO ₃→CaCO ₃↓+2Na ⁺

The bittern that last operation is come adds and Mg ^A+Equivalent milk of lime, reaction generates magnesium hydrate precipitate, supernatant liquor is extracted into another container adds and Ca ²⁺The reaction of normal soda ash generates calcium sulfate precipitation, supernatant liquor is entered down in the solar pond of operation and stores up halogen.More than two kinds of throw outs separate processed, water recycling, filter cake is as chemical industry and composite fertilizer material.

(6) solar pond thermal-arrest, heat accumulation, evaporation concentration and and storage halogen

Can utilize the gradient difference function of high salinity bittern in the solar pond, absorb solar radiation, carry out thermal-arrest, heat accumulation, initiate bittern is played the effect of heat temperature raising evaporation concentration, bittern concentration is raised to 18 ° of Be, temperature 〉=45 ℃, evaporation fresh water amount 22.7Kg/m ³, from the 1st step so far the step volume be 1m ³3.5 ° of Be seawater simmer down to 0.1673m ³18 ° of Be bittern.

(7) heat pump low-temperature evaporation concentration systems

Utilize " low temperature high-efficient energy-saving evaporation process " (number of patent application 200810219214.2), with the heat pump compression low temperature heat energy is become high temperature heat, temperature 〉=90 ℃, adding hot brine evaporates, utilize the heat pump refrigerating function in addition, reduce temperature≤15 ℃ of water in the Water Jet Condenser, improve vaporization efficiency, reduce cooling water amount.From brine temperature 〉=45 that the 6th step is come ℃, concentration is 18 ° of Be, and behind heat pump low-temperature evaporation concentration systems, bittern concentration is raised to 25 ° of Be, temperature 〉=60 ℃, and evaporation fresh water amount is 55Kg/m ³, from the 1st step so far the step volume be 1m ³3.5 ° of Be seawater simmer down to 0.112m ³25 ° of Be bittern.

(8) Compression Evaporation crystallization salt making system

Bittern concentration is a saturated bittern when being 25 ° of Be, sodium-chlor will be separated out in crystallization when being concentrated to 26 ° of Be, this is the evaporative crystallization salt producing craft. adopt N to imitate secondary steam Compression Evaporation crystallization processes, every effect evaporation area is equal substantially, first heating steam pressure 〉=the 2.2MPa of imitating, temperature to 125 ℃, all the other respectively imitate working pressure, temperature is according to throughput, vapour compressor technical parameter and crystallizer specification and decide, the continuous feeding discharging material of native system is the following current flow process, dump temperature≤65 ℃, bittern concentration is 28 ° of Be, and each imitates compression heating steam, gathers behind the flash evaporation device, the water vapor recompression improves temperature to 140 ℃, again as the thermal source of product drying.

(9) the ion exchange crystallization in motion is sized mixing

The salt slurry that the 8th step is discharged carries out solid-liquid separation, and solid salt adds fresh brine sizes mixing, and realizes the effect of ion exchange crystallization in motion, and the salt crystalline particle is increased, and increases output, ensures the quality of products.The old bittern of 28.5 ° of Be is fully utilized production compoiste fertilizer raw material.

(10) waste residue and liquid processing implementation step is as follows:

In production process a large amount of waste residue and liquid dischargings are arranged, these materials are to produce the compoiste fertilizer good raw material, and for save energy, to produce liquid fertilizer, solid-state is auxilliary.

1. the throw out of sea water preprocessing after filtering, filter cake do to be produced solid-state fertile raw material, by solid-state fertile Technology standard, adding, mixes through the heapization fermentation with other nutrients with hygrometric state is the fertilizer that ferments.

2. calcium-magnesium removing ionic throw out is magnesium hydroxide and lime carbonate, is the indissoluble thing, and its treatment process is as follows:

A: lime carbonate can be used as the stopping composition of solid-state fertilizer, the sclerosis place of also can banketing.

B: magnesium hydroxide neutralization reaction.

Magnesium hydroxide and sulfuric acid carry out neutralization reaction, generate sal epsom liquid, and a part can be liquid fertile raw material, and rest part is as the sal epsom product.

3. after bittern was concentrated into 16 ° of Be process calcium-magnesium removing ions, essential substance had Nacl, Na in the bittern ₂SO ₄And Kcl, in the crystallization salt-making process, most sodium-chlor is separated out, and when bittern was 28 ° of Be, these three kinds of materials still existed, and can implement saltcake Repone K method and produce vitriolate of tartar:

Transform the principle of producing vitriolate of tartar by mining design research institute of the Ministry of Chemical Industry according to saltcake and Repone K, the design technological process of production is used relevant phasor and the fast decomposition and crystallization principle of control.Control its mutual conversion condition, the Repone K transformation efficiency was improved more than 10% than originally, and the mother liquid evaporation amount reduces than original technology

Controlled too fast replacement(metathesis)reaction speed, product crystalline particle degree has been increased, and adopt mother liquor direct evaporation knot to replace freezing denitrating technique, vitriolate of tartar purity is reached more than 98%, byproduct sodium-chlor purity improves, and chloride ion content is less than 0.5%.

Reaction formula

Kcl+Na ₂SO ₄→NaKSO ₄+Nacl

Kcl+NaKSO ₄→K ₂SO ₄+Nacl

(11) other steps are undertaken by traditional chemical technique, and are identical as centrifuge dehydration, drying, sub-sieve, metering and packing etc.

Claims (1)

1. one kind is utilized wind energy, sun power and heat pump techniques to carry out the technology that sea water desaltination, salt manufacturing and byproduct thereof fully utilize, and it is characterized in that by following processing step:

(1) takes out and receive seawater

Utilize the pipeline extracting seawater, the seawater saltness is 〉=3.5 ° of Be;

(2) seawater physico-chemical pretreatment

At first using the milk of lime of pH value＞12 to transfer the pH value of seawater is 8, adds PH again and be 4.5 polymeric aluminum chlorides solution, and the pH value that makes seawater is 6～6.5 to reach iso-electric point, clarifies then, and the water after the clarification uses for next step; Sediment water is not through there being the dehydration of band vacuum filter, and water repeats reuse, and filter cake is as composite fertilizer material;

(3) adopt reverse osmosis seawater desalination system system tap water and high-concentrated brine

Adopt reverse osmosis seawater desalination system, its flow process is continuous convergent technology, and the group body device is three grades, and every grade all has recuperator and boosting pump, and operating pressure at different levels are at 5.5～11MP ₂In the scope, power consumption is controlled at 2～5kw.h/m ³

Seawater is after desalination, and the bittern saltness rises to 14 ° of Be, 1m by 3.5 ° of Be ³3.5 ° of Be seawater simmer down to 0.245m ³14 ° of Be bittern; Can produce fresh water 750kg after every cubic metre of seawater cleaning, wherein 10% fresh water is made tap water after uf processing, all the other 90% conduct life and agricultural waters;

(4) air blows the bromine system

Bittern concentration is 14 ° of Be after reverse osmosis system desalination, in temperature 〉=30 ℃, under the condition of pressure≤1.5Mpa, utilize ejector to add acid and chlorine, make bittern acidifying and oxidation, make bromide anion become monomers B r liquid, spray into toward dirty from cat head, pressurized air is gone into from the tower pucking,, water vapor and bromine are taken out of outside the tower with the reverse convection current in tower of bromine liquid, through technology system bromines such as absorption, condensation and separation, make bittern obtain evaporation, concentration reaches 16 ° of Be, evaporation fresh water amount 55Kg/m ³, 1m ³3.5 ° of Be seawater simmer down to 0.19m ³16 ° of Be bittern;

(5) analyse except that Ca ²⁺, Mg ²⁺Ion

The bittern that previous step is come suddenly adds and Mg ²⁺Equivalent milk of lime, reaction generates magnesium hydrate precipitate, supernatant liquor is extracted into another container adds and Ca ²⁺The reaction of normal soda ash generates calcium sulfate precipitation, supernatant liquor is entered down in the solar pond of operation and stores up halogen, more than two kinds of throw outs separate processed, water reuses, filter cake is as chemical industry and composite fertilizer material;

(6) solar pond thermal-arrest, heat accumulation, evaporation concentration and and storage halogen

Utilize the gradient difference function of high salinity bittern in the solar pond, absorb solar radiation, carry out thermal-arrest, heat accumulation, bittern is evaporated concentrated, make bittern concentration be raised to 18 ° of Be by 16 ° of Be, temperature by normal temperature be raised to 〉=45 ℃, evaporation fresh water amount 22.7Kg/m ³, 1m ³3.5 ° of Be seawater simmer down to 0.1673m ³18 ° of Be bittern;

(7) heat pump low-temperature evaporation concentration systems

Utilize low temperature high-efficient energy-saving evaporation process, low temperature heat energy is become high temperature heat, temperature 〉=90 ℃ with heat pump compression, add hot brine and evaporate, utilize the heat pump refrigerating function in addition, reduce temperature≤15 ℃ of water in the Water Jet Condenser, improve vaporization efficiency, reduce cooling water amount; From brine temperature 〉=45 that step (6) is come ℃, concentration is 18 ° of Be, and behind heat pump low-temperature evaporation concentration systems, bittern concentration is raised to 25 ° of Be, temperature 〉=60 ℃, and evaporation fresh water amount is 55Kg/m ³, 1m ³3.5 ° of Be seawater simmer down to 0.112m ³25 ° of Be bittern;

(8) Compression Evaporation crystallization salt making system

Bittern concentration is a saturated bittern when being 25 ° of Be, sodium-chlor will be separated out in crystallization when being concentrated to 26 ° of Be, adopt N to imitate secondary steam Compression Evaporation crystallization processes, every effect evaporation area is equal substantially, first heating steam pressure 〉=the 2.2MPa of imitating, temperature to 125 ℃, all the other respectively imitate working pressure, temperature is according to throughput, vapour compressor technical parameter and crystallizer specification and decide, the continuous feeding discharging material of native system is the following current flow process, dump temperature≤65 ℃, bittern concentration is 28 ° of Be, and each imitates compression heating steam, gathers behind the flash evaporation device, the water vapor recompression improves temperature to 140 ℃, again as the thermal source of product drying;

(9) the ion exchange crystallization in motion is sized mixing

The salt slurry that step (8) is discharged carries out solid-liquid separation, and solid salt adds fresh brine sizes mixing, and carries out the ion exchange crystallization in motion, and former crystalline particle is increased, and increases output, the old bittern of 28.5 ° of Be is fully utilized produce the compoiste fertilizer raw material;

(10) waste residue and liquid processing implementation step is as follows:

1. the throw out of sea water preprocessing after filtering, filter cake do to be produced solid-state fertile raw material, by solid-state fertile Technology standard production;

2. calcium-magnesium removing ionic throw out is magnesium hydroxide and lime carbonate, and its treatment process is as follows:

A: lime carbonate is as the stopping composition of solid-state fertilizer or the sclerosis place of banketing;

B: magnesium hydroxide neutralization reaction

Magnesium hydroxide and sulfuric acid carry out neutralization reaction, generate sal epsom liquid, and a part is liquid fertile raw material, and rest part is as the sal epsom product;

3. utilize the essential substance Nacl, the Na that produce in the bittern concentration process ₂SO ₄And Kcl, implement saltcake Repone K method and produce vitriolate of tartar:

(11) other steps such as centrifuge dehydration, drying, sub-sieve, metering and packing etc. are undertaken by traditional chemical technique.